Former Genzyme CEO, Henri A Termeer, who had spent 26 years in the position, left Genzyme following the takeover. The company had since been without a CEO until Meeker's appointment.

Christopher A Viehbacher, CEO of Sanofi, said: "After working closely with David over the past six months, I am confident that he is the best person to lead Genzyme. David's commitment to employees, physicians and patients has been a key success factor in the successful integration of Genzyme as part of the Sanofi Group."

Under Meeker's leadership, Genzyme will incorporate the rare disease business and the multiple sclerosis franchise.